IFE Target Fabrication, Delivery,and Cost Estimates

N. B. Alexander, L. Brown, D. Callahan, P. Ebey, D. Frey, R. Gallix, D. A. Geller, C.Gibson, J. Hoffer, J. Karnes, J. Maxwell, A. Nikroo, A. Nobile, C. Olson, N. Petta, R.

Petzoldt, R. Raffray, W. Rickman, G. Rochau, D. Schroen, J. Sethian, J. D. Sheliak, J.Streit, M. Tillack, E.I. Valmianski

Presented by Dan Goodin

at the

Fusion Power Associates Annual MeetingAnd Symposium

Oak Ridge, TennesseeDecember 4-5, 2007

Main messages and conclusions of this talk…….

1. IFE target technology builds upon the larger ICF program

- Not starting from “zero” for IFE

- Large effort for NIC fosters efficiency (e.g., foam shells)

2. The recent IFE target technology (“mass production”) work hasbeen on laser fusion- High Average Power Laser (HAPL) program

- Heavy Ion Fusion and Z-pinch targets briefly noted briefly here

3. For laser fusion:- All process steps identified; suitable for mass production

- Ongoing work = near-term laboratory demonstration of

feasibility for each step

Good progress has been made on these laser fusion

demonstration programs….

Target development is an essential component ofany inertial fusion concept…

• Three main IFE concepts

- Strong synergism but key differences that lead to specific technologies

Heavy Ion FusionLaser Fusion

Z-Pinch IFE (ZFE)• Foam capsule with

overcoat

HIF Distributed Radiator SNL Dynamic Hohlraum

• Advanced

manufacturing methods

• Emerging

requirement’s &

concepts

DT Vapor

Foam + DT

Thin

High Z coating

2.3

mm

CH Overcoat

DT

Lowdensitymetalfoams

Key = time fortransport &

loadingz (mm)

r (m

m)

BA

CD

6

4

2

0

E

420 8 10

K L

M

HN

I

E

G

6

J

F

historical

NRL High Gain Target

Top level target technology requirements

• Basic requirements

- Supply about 500,000 targets per day for a ~1000 MW(e) laser fusionor HIF power plant (~88,000 for ZFE at 0.1 Hz, 10 chambers)

- Do it cheaply, each laser fusion/HIF target has an energy value ofabout $3.00 ($22.50 for ZFE)

Specific target requirements have been defined to varying degrees…

SOMBRERO 3-D model

for neutronics analysisLaser Fusion

HIF - HYLIFE-II ZFE

An initial cost analysis has been done for an“nth-of-a-kind” IFE target manufacturing

Goodin, D.T., et al, “A cost-effective target supply for inertial fusion energy”, Nuclear Fusion 44 (2004).

160’

100’

QA/QC Lab

Control Room

Foam Shell Generation

Seal Coat Formation

CO2 Drying

High-Z Sputter

CoatingDT Filling

DT Layering

Target Injection

Conceptual layout for target fabricationfacility, ~500,000 targets per day,standard engineering cost factors

While developmentprograms are stillsignificant, cost

studies are promising!

Reactor

• Major “paradigm shift” from current day

• Installed capital ~$97M, annual operating $19M est’d 16.6

cents/target EliminatingFOAK CostsEliminatingFOAK Costs Reducing

CharacterizationReducing

CharacterizationIncreasingYield

IncreasingYield Increasing Batch

SizesIncreasing Batch

Sizes

Outline of processes for the HAPL target supply

Micro-encapsulation

1) Fabricatefoamcapsules

2) Overcoats3) DT Fuel

Layer4) InjectTarget

5) TrackTarget

Optical systems

Highlyisothermalenvironment

Layering

cryostat

A) Interfacial

reaction

B) GDP coating

Fluidizedbed

C) Sputter coating of

metal (Au/Pd)

FTF-sized (2.4mm OD) foam

capsules

Shuttle

S/C

Coil

~40 cm

Accelerator(~50-100 m/s)

“glint” for

tracking

1) We can make the HAPL foam capsule (divinyl benzene)

• Systematic, parametric studies have led to ability to control capsuleparameters (material, OD, wall thickness, sphericity, density……)

Better NC

Poor NC

1mm

Non-concentricity(NC) is a “wall

uniformity”defect

0%

20%

40%

60%

80%

100%

0 1 2 3 4 5 6 7 8 9 10

% Non Concentricity

Pe

rce

ntile

Cure OptimizationExperiment

Updated controls -July 2006

Controls March2006

2005

July-Aug 20045%

5%

60%

50%

Pe

rce

nt

Pro

du

ct

Yie

ld

DVBProgress

Do we meet foam capsule requirements?divinyl benzene (DVB) and resorcinol formaldehyde (RF)

Inprogress

Pass(~60% of

shells <3%NC)

Pass(<0.3%)

Pass(~1 um)

Pass(97± 5

mg/cc)

Pass(± 20um)

Pass0.025mm

range

DVB

Contact radiography todetermine density variation.

In progressModes100 to500

< 0.3%Areal density

ImprovingIn Progress(10% of

shells <3%NC

--< 1-3%of wallth.

Non-concentricity

Measured on dry foam shellsBorderline(1%

average)

--<1 % ofradius

Out of round

Based on SEMPass(~0.01 um)

<3 µmPore size

Pass[25%]20-120mg/cc

Density

RF is a more recentdevelopment

In progress± 20180 µmWallthickness

Real-time feedback controldemonstrated

Pass± 0.06 mm

range

± 0.24.6 mmDiameter

CommentsRFTolerance

ValueAttribute

2) It’s the overcoat …(it must be gastight as well as have a “smooth” surface finish)

(PVP/GDP),Interfaciallayer to coverpores, GDP toseal….

0

2

4

6

8

10

12

0 1 2 3 4 5 6 7 8

PVP thickness ( µm)

GD

P t

hic

kn

ess

(µ

m)

>=50%

<50%

0%

PVP

DVBGDP

5 m

Current Spec

<10 microns

Potential pathways for overcoat:

1. Interfacial reaction

2. Direct (GDP) coating (withsmaller-pore RF)

3. 2-step process w/ interfacialplus a GDP coat

DVB holds gas, but pinholes…

2) A current focus is on the overcoat…

0

200

400

600

800

1000

1200

0 10 20 30

GDP coating thickness (um)

D2 H

alf life

(se

c)

Pinhole free

Pinholes

Predicted D 2

permeation rate

Pinhole free

Leak Mechanisms:

Leak too fast to

test at cryo temp

Ugly – viscous flow leak

-22

-20

-18

-16

-14

-12

0

50

10

0

15

0

20

0

25

0

30

0

35

0

40

0

45

0

T ime (seconnds)ln

(M

S

ion

sig

nal)

-22

-20

-18

-16

-14

-12

0

20

0

40

0

60

0

80

0

10

00

12

00

14

00

16

00

18

00

T ime (seconnds)

ln

(MS

ion

sig

nal)

LN2 temp

Bad – pinhole leak

-22

-20

-18

-16

-14

-12

0

50

0

10

00

15

00

20

00

25

00

30

00

T ime (secoonds)

ln

(MS

ion

sig

nal)

LN2 temp

Good – permeation leak only• D2 testing, leak rate measured with

mass spectrometer

The shells are tested to be “gas tight” and cansurvive cryo cooling and warming cycle

GDP on RF

Overcoated R/F foam shells are also smootherthan coated DVB shells

Optical Profiler (WYKO)measurements

acquired at 20x, with a

300 x 200 um area

Surface Roughness of HAPL Coated Foam Shells(> 4 mm diameter)

Shell/CoatingType:

DVB/PVP DVB/PVP/

GDP

RF/GDP

“Spheremapper”

• Our ultimate test of surface finish

• Power Spectrum of Surface Roughness

• GDP/RF = 42 nm RMS for modes 50 to 10001E-1

1E+0

1E+1

1E+2

1E+3

1E+4

1E+5

1E+6

1 10 100 1000

Mode Number

Po

wer

(nm

^2)

3) Mass production layering experiment is beingbrought online …

Cryogeniccirculator

Cryocoolers

HeliumCompressors

Deuteriumbooster pump

• Static controlled

• Scoping tests show randomization

• Initial cryostat cooldowns to ~ 11K

• Method to “grab” one shell forcharacterization has been done atcryogenic conditions

Shells at 11 Kelvin

Gassupply(He)

8 metergun

barrel

Gasremoval

equipment

Trackingsystems

Simulatedtargetchambercenter (~25meters totallength)

Injectiondemo for>400 m/s

(4) Target injection has several acceleration options …

Magnetic diversion - reducesgas in chamber and heatingand give more options

1. “Mechanical” (~50-100 m/s)

2. EM “Slingshot” (~60-85 m/s)

5) Tracking and alignment concepts identified anddemonstrations underway• Requirement is alignment of lasers and target to 20 µm

• System using lasers, optics and fast steering mirror• Also - “glint” from target ~1 ms before the shot aligns optical

train (target itself is the reference point)

(target)

Scaled experiment, velocity ~

5 m/s

Accuracy of hitting “on-the-fly” is ~125 microns now (1 )

Working toward 20 micron

goal for demo

Fast steering

mirror for demo

(commercial)

Summary and conclusions

1. IFE target technology is leveraging the ICF

program to maximum extent possible

2. Target supply scenarios have been identified for

the laser fusion target supply

3. The HAPL program emphasis is on near-term

laboratory demonstrations of feasibility

Backup slides

To the future - integration of cryogenics w/ injector

Target fab labs

Cryogenic target supply systems

Differential vacuum pumping

Sabot deflector

Surrogate target chamber

In-chamber tracking

Low power hit on fly laser

Position detectors

Gun barrel Loading chamber

M. S. Tillack et al, “A TargetFabrication and Injection Facility

for Laser-IFE” SOFE-2003 14-17October 2003, San Diego CA.

Mass layeringdevice

Injector

Concept fromSOFE- 2003

ZFE target conceptual design allows an initialcost comparison for all three concepts

Assumptions:- developmentprograms done

- nth-of-a-kind plant- does not include RTL

• ZFE “target load” has liquid

hydrogen cooling buffers

• Allows temperature control

during loading process

IFE

Concept

Target

Design

Target

Yield

(MJ)

Est'd

Cost/target

for 1000

MW(e)

% of

E-value

Laser FusionDirect drivefoam capsule ~400 $0.17 ~6

HIF

Indirect drivedistributed radiator ~400 $0.41 ~14

ZFE

Dynamichohlraum"target load" ~3000 $2.86 ~13

IFE Target Cost Comparison

Goodin, D.T., et al, “A cost-effective target supply for inertial fusion energy”, Nuclear Fusion 44

(2004), S254-265.

HIF - laser-assisted chemical vapor deposition (LCVD) tomanufacture the HIF hohlraum

• Low-density, high-Z only materials needed

• Proposed concept - micro-engineered matl’s– Build from “inside out”, avoid machining

and handling low-density foam

3D-LCVD hohlraumfabrication

Maxwell, James, et.al., A Process-Structure Map for Diamond-like Carbon Fibers from 1-Ethene at Hyperbaric

Pressures, Advanced Functional Matl’s, 15, 7, 2005, 1077-1087.

Arrays demo’dvia DiffractiveOptics; enableslow-densityblocks andengineeredfoams.

LCVD for alloys

of normally

immiscible

materials (NIM’s)

Si-W Alloy

Fibers

Goodin, D.T., et al, “Progress in Heavy Ion Driven Target Fabrication and Injection”,

Nuclear Instruments and Methods in Physics Research, A, Vol 544, 2005, 34-41,

systems for Z pinch drivenIFE are being developed

.... Design concepts have been prepared indicating time frames

for cryogenic target assembly and handling are feasible

Vacuum Chamberw/ Assembly Robots

Insertion of Target AssemblyInsertion of Wire Array

Wire ArrayAssemblies Filled and Layered

Cryogenic TargetAssemblies

Flibe-protected ZFE

chamber conceptFlibe-protected ZFE

chamber concept

Assembled RTL/target

in transit

Removable

lid

Target Assembly Station

Be capsule

Liquid H2 “buffers”

Plant Design Data

Rep-rate = 0.1 Hz

Yield = 3 to 20 GJ

Power = ~1100 MW(e)

See “ZP-3, A Power

Plant Utilizing Z-Pinch

Fusion Technology”,

Rochau et al. IFSA2001

1) Production rate ~500,000 targets/day - 1000 MW(e)plant

2) Pb/Hf (70:30) is high Z material (single use)3) Installed capital cost ~ $304M ($38 M annualized

cost)4) Annual materials and utilities ~$11M5) Annual maintenance costs (labor and materials)

~$18M6) Annual operating labor costs ~$10 M7) Cost per injected target is estimated at ~40.8¢

each(~32¢ each for 3000 MW(e), ~22¢ each for centralized

production) 100’

PS shell

generation

Ethanol/Water Exchange

& Vacuum Drying

DT Filling

(Permeation

Cells)

Layering

(Fluidized Bed)To

Chamber

QA/QC Lab

80’

Injector

Hohlraums

Hohlraum

Production

Area

~1.4m

Hohlraum

Cryo-

AssemblyTFF layout for capsule,

filling, layering, injection

LCVD systems

are major

capital cost

Estimates for indirect drive (HIF) targetproduction costs

Assumptions:

1) R&D programs done

2) Major “paradigm shift” from

current targets - no first-of-a-kind

costs, statistical characterization,

increased yield, larger batch sizes

3) “nth-of-a-kind” plant, standard

engineering cost factors

2) How well are we meeting the overcoat specs…?

Fail at10 um

> 500nm

+/- 2 µm

PVP/GDP(CHO)

DVB

For a >20 um thick coating> 2 atm--TBDStrength (forfilling)

For current techniquesrequire ~20 um thickness,working to minimize

Fail at10um,somegood at >20 um

--TBDPermeability(gas tight)and yield

Gettingclose (50 -200 nm)

--<50 nmPowerspectrum(surfacefinish)

+/- 2 µm+/- (30 –300) nm

<5-10µm

CoatingThickness

N, O now acceptableGDP (CH)CHNOCoatingcomposition

CommentsRFToleranceValueAttribute

These specs are evolving as moresimulations are done by the designers

The DVB capsule meets the sphericityspecification, but RF still requires work

• The yield of RF shells that meet the 1% of radiusOut-of-Round (OOR) specification is 70%

0.0

20.0

40.0

60.0

0 5 10 15 20

Shell #O

OR

(m

icro

ns)

RF Shell DataDVB Shell Data

A possible fix for this is to increase the interfacialtension of the RF system before curing

OOR = (max radius – min radius)

0

20

40

60

0 5 10 15 20

Shell #

OO

R (

mic

ron

s)

100% Yield 70% Yield

max radius

min radius

Currently DVB shells have a better yield of shells thatmeet the wall uniformity specification

DVB is better for the NC specification (at the moment)

thickness shell avg.

offsetNC =

• Uniformity defined in terms Nonconcentricity (NC)

Offset = distance between centers

of inner and outer wall

Percentile Plot of Foam Wall Uniformity